container.get(i) will return the object at the i position in the array list.

It almost looks like you are wanting to call a method on that object that is returned. To do that you will want to do something like this:

Java Code:

//Say the array is containing objects of type MyObject
((MyObject)container.get(i)).myMethod();

A better way is to use the new Java types with your containers. Like so

Java Code:

private ArrayList<MyObject> container = new ArrayList<MyObject>();
public Test()
{
for( int i = 0; i < container.size(); i++)
{
//Now you can do things like this
container.get(i).myMethod();
//Because the container knows it is holding an object of type MyObject
}
}